Process Street (the backend):

Install Homebrew (if Mac) or Linuxbrew (if Linux)

Install PostgreSQL

Note

brew will probably install the latest version of postgresql, but it's preferable to have the same version as on production to avoid issues with syntax incompatibility. Current version on the production server is 9.3.

Procedure for Mac/Linux

From the Terminal app:

brew install postgresql

brew services start postgresql

createdb USERNAME

psql

Troubleshooting. In some cases, there is might be an issue when starting postgresql: